[cisco-voip] Rightfax transmission errors

[Sreekanth Narayanan (sreenara)]

Hi Frank,

Based on the working faxes between the VG224s and the RF, we can say that the network is stable. And you don’t seem to have seen the RTN with this flow.
We can also say that both devices in this call flow work fine.

Now when you make calls from the VG224s to the PSTN, the fax machines behind the VG report successful faxes.

The questions that you need to answer to move forward on this:

1.       Are you trying the same PSTN destination number from both RF and the VG224s?

2.       What’s the difference in the network topology between the VG224 – PSTN call and RF – PSTN call?

3.       Have you taken logs or packet captures for the successful call from the VG224 to the PSTN, and checked if there is an RTN message in that one as well, but the machine reports the call as successful when the call continues and ends? Maybe it’s the difference in the way that fax machine handles the RTN and the RF handles the RTN?

4.       PCM captures from the PRI gateway for the RF and the VG224 calls would also be helpful.

Thanks
S

From: cisco-voip [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Frank Arrasmith
Sent: Tuesday, December 15, 2015 5:59 AM
To: cisco-voip at puck.nether.net
Subject: [cisco-voip] Rightfax transmission errors

Hi All,
   We have recently transitioned to Rigthfax SR-140 Virtual server from physical board server and we are having trouble when receiving faxes from what appear to only be other fax servers.  We see consistent failures from the fax server sending side, but when having the the sender try from a real fax machine, the fax goes through no problem. Packet captures do not indicate any failure to switchover to t.38, but we will see an RTN message but the call still completes. The RF will still mark the fax as transmission error. sometimes the Fax image shows black , but mostly will be acceptable. Our VoIP network is very stable and we run several internal faxes(on VG224s/vg350's) to and from the rightfax server with no issues. setup is as following. i can post more config is someone is able to help out. I have a case open with Cisco TAC, but they are taking their time to respond.
External:
TDMPRI-->c3925 - IOS 15.2.4(M6) --SIP t.38 w/redundancy--> CUCM V9--SIP Trunk --> RF 10.5 t.38only(per RF vendor recommendation), v.34 disabled, MH compression.
Internal:
Fax machine--> vg224/vg350--> MGCP T.38 with redundancy--> CUCMV9IP Trunk --> RF 10.5 t.38only(per RF vendor recommendation), v.34 disabled, MH compression.
Thanks for any help in advance.
-Frank
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